1. Field of the Invention
The present invention relates to an apparatus for closed kinetic chain muscle strengthening and/or rehabilitation of the shoulder joint and the upper limb.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
It has been observed that the pathologies of the deep tendons of the shoulder (rotator cuff) are very frequent, and that the ultimate evolution of this tendinous pathology is the fracture.
Studies have shown that up to the age of 70 years, 50% of the persons suffer from a fracture of the cuff and that at the age of 80 years, it reaches 70%. The therapists are thus daily faced with this kind of pathologies, and the aging of the population increases the frequency of this problem.
Most of the time, the upper limb is used by the person in an open kinetic chain, the hand remaining movable. This use of the upper limb in an open kinetic chain highly stresses the muscles of the rotator cuff and favors the decentering, which in the end cause evolutionary tendinous lesions.
In order to cope with these problems, open kinetic chain rehabilitation techniques are carried out, which, though they are indispensable, have however drawbacks. The open kinetic chain strengthening of the depressor muscles favor the decentering, and the strengthening of the lateral rotators produces deleterious stresses in the supraspinatus.
The present applicants have observed that the closed kinetic chain load of the upper limb permits, under certain circumstances, to take part in the re-centering of a decentered head of humerus. From this observation resulted a new closed kinetic chain active glenohumeral re-centering technique guided by the practitioner.
According to this technique, the patient raises the arm in the plane of the scapula, or slightly in front of this plane, until it is located in the extension of the subcutaneous portion of the spine of the scapula, eventually a little below if the position is painful or uncomfortable. This permits with certainty to have between the plane of the glene (articular surface of the scapula) and the axis of the diaphysis of the humerus, an angle (open outside and below) larger than 90°. In some cases, namely when the anterior decentering of the head of the humerus on the scapular glene is important, the position of the upper limb will be slightly changed. The arm will then be raised in flexion or in an intermediate position between the flexion and the abduction in the plane of the scapula.
The adequate position is determined by the practitioner, and once it has been reached, the latter firmly holds the patient's hand and asks him to perform traction or pushing movements, successively and/or alternately, preferably without either flexing the elbow or raising the shoulder, and maintaining the contraction during a determined period of time.
This rehabilitation technique provides good results, but its implementation has some drawbacks, and namely in that it permanently requires the practitioner's participation. This closed-chain work corrects the decentering of the glenohumeral joint.
In order to cope with these drawbacks, an apparatus for closed kinetic chain muscle strengthening and/or rehabilitation of the shoulder joint and the upper limb is provided, which permits the implementation of the active re-centering technique without intervention by the practitioner, except for its placing and monitoring, and which permits a work performed in a repetitive, quantified and measured way. It should be noted that this apparatus is not only for rehabilitation work, since it is also usable for preventive or muscle-training purposes.
It should be noted that apparatuses for muscle strengthening and/or rehabilitation of the shoulder joint and the upper limb are already known. All these apparatuses include means for positioning the user or patient, a working assembly comprising resisting means enabling the user or patient to exert efforts, support means that connect said working assembly to said positioning means, and provided with adjusting means permitting to position and orientate said working assembly in space.
This is for example the case for U.S. Pat. No. 5,830,160, which describes an apparatus for evaluating the performance of a movement, by measuring the stress forces generated during a movement guided along a desired path. This apparatus, which is in particular intended for the rehabilitation of persons suffering from brain damage, cannot allow the implementation of the above-mentioned technique, since it does not allow making efforts with a stretched or slightly flexed arm, in a particular direction, and in particular in the extension of the subcutaneous portion of the spine of the scapula.
U.S. 2004/082437 describes an apparatus permitting to extract isokinetic measures from the torque applied by part of the body, the latter performing a pivoting or flexing movement at a given angular speed about an effective pivoting axis. Even if transformed to permit working along the axis, this apparatus would not permit to implement the above-mentioned technique.
U.S. Pat. No. 6,227,047 describes an apparatus comprising an adjustable horizontal arm coupled to a vertical element on which it adjusts vertically. The horizontal arm is provided with isokinetic measuring means. This apparatus does not permit a user or patient to position its arm according to the prescribed angle to perform the work required in the above-mentioned technique.
U.S. Pat. No. 4,817,943 relates to a physical exercise apparatus designed for developing the muscles of the shoulders. This apparatus permits the user to carry out shoulder rotation exercises with flexed arms, and it is neither adapted nor adaptable to the implementation of the above-mentioned technique.
FR 2 674 136 provides a shoulder rehabilitation device, in order to ensure a pivoting movement of the joint about a determined axis, while exerting on the limb an adjustable pulling force so as to perform a distraction of the joint. This device does not permit to implement the above-mentioned technique, and in addition it produces opposite effects, since it leads to exert a pulling force on the joint.
None of the apparatuses for muscle strengthening and/or rehabilitation of the shoulder joint and the upper limb known hitherto permits to implement the above-mentioned rehabilitation technique.